http://gcc.gnu.org/onlinedocs/gfortran/ISO_005fFORTRAN_005fENV.html lists ISO_FORTRAN_ENV. The standard is marked as Fortran 2003 but INT{8,16,32} and REAL{32,64,128} are Fortran 2008
r148317 | burnus | 2009-06-09 19:21:45 +0200 (Tue, 09 Jun 2009) | 9 lines 2009-06-09 Tobias Burnus <burnus@net-b.de> [...] * intrinsic.texi (ISO_FORTRAN_ENV): Document INT{8,16,32,64} and REAL{32,64,128}. Closing.